CN110380811B - Visible light safety communication method based on artificial interference technology - Google Patents

Visible light safety communication method based on artificial interference technology Download PDF

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CN110380811B
CN110380811B CN201910735834.XA CN201910735834A CN110380811B CN 110380811 B CN110380811 B CN 110380811B CN 201910735834 A CN201910735834 A CN 201910735834A CN 110380811 B CN110380811 B CN 110380811B
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formula
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visible light
artificial interference
eavesdropper
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CN110380811A (en
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张文胜
田丁卉
刘玉
孙健
王承祥
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Shandong University
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
    • H04B10/114—Indoor or close-range type systems
    • H04B10/116—Visible light communication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K1/00—Secret communication
    • H04K1/02—Secret communication by adding a second signal to make the desired signal unintelligible

Abstract

The invention relates to a visible light safety communication method based on an artificial interference technology, wherein the system comprises an information sender, a legal receiver and a plurality of illegal eavesdroppers, and the eavesdroppers do not interact with each other. When a sender and a legal receiver normally communicate, an eavesdropper can monitor and acquire information in a channel. The system can still meet the requirement of safe communication by adjusting the quantity of the light sources or the power ratio of the effective information and the artificial interference information under the condition that the position information and the quantity information of the eavesdropper are unknown. The invention calculates the secrecy rate based on the system model, and is beneficial to flexibly selecting the power ratio of effective information and interference information in the input signal according to the required security level. Meanwhile, the security performance of the system can be improved by increasing the number of the light sources.

Description

Visible light safety communication method based on artificial interference technology
Technical Field
The invention belongs to the technical field of visible light communication physical layer safety, and particularly relates to a visible light safety communication method based on an artificial interference technology.
Background
With the popularization of commercial and intelligent devices of 5G communication networks, network requirements become higher and higher, and traditional wireless spectrum resources become in short supply, which restricts the development and application of next generation wireless communication. Visible Light Communications (VLC) is a wireless communication method that has emerged to alleviate the shortage of spectrum resources today. VLC uses visible light as an information carrier to directly transmit light signals in free space. As one of potential technologies of the 6G mobile communication network, VLC has advantages in that: firstly, the product is green and safe and harmless to human bodies; secondly, illumination and communication are simultaneously realized, and the flicker frequency of the LED is higher than that of human eyes through the rapid on-off control of the LEDThe frequency can be identified for simultaneous communication and illumination; third, the frequency spectrum resource is rich, and the unauthorized visible light frequency band of 3.8 is multiplied by 1014Hz～7.9×1014Hz, which is not interfered by radio frequency signals; fourthly, the frequency of the visible light is extremely high, and the high-speed communication requirement can be met only by adopting a proper technology.
Physical-layer security (PLS) is a complement to upper layer security, and uses jamming and channel randomness to reduce information received and correctly detected by unauthorized eavesdroppers, thereby improving the security performance of the communication system. Currently, common physical layer security techniques include channel coding, key agreement, cooperative interference, and the like. Shannon, c.shannon, 1949 proposed the best way to keep secret as a word. In 1975, d.wyner proposed a discrete memoryless channel-based eavesdropping gaussian channel model, which has three roles: the message sender Alice, the legitimate receiver Bob, and the eavesdropper Eve, illegally acquire signals in the channel while Alice and Bob normally communicate. The link between Alice and Bob is a legal channel, and the link between Alice and Eve is an illegal channel. Wyner considers that there is always a coding scheme that allows a legitimate receiver to correctly receive and demodulate the information from the sender, while an eavesdropper cannot get any information. Wyner gives the definition of the secret capacity, and the physical meaning of defining the secret capacity is the maximum transmission rate that the system can achieve under the condition that an eavesdropper cannot receive any information. In 1978, the mathematical expression forms of the secret capacity are respectively given by I.Cssizui and K.Leung-Yan-Cheong on the basis of a Wyner eavesdropping channel model. The secrecy capacity, as an upper limit of the secrecy rate, is one of important indexes characterizing the security characteristics of the communication system. The secret capacity may be calculated by differencing the channel capacity of the legitimate channel and the channel capacity of the eavesdropping channel. Let Alice send a signal x and Bob and Eve receive information yBAnd yEThe channel capacities of the legal channel and the eavesdropping channel are CBAnd CEThe privacy capacity of the system can then be expressed as: cS＝max{CB-CE0, where max {, · denotes taking the larger value between the two.
The closed form of the secret capacity of the conventional radio frequency communication system can be derived by combining the above mathematical expression with the shannon formula, but cannot be directly applied to the visible light communication system, because: the input signal of the radio frequency communication system is bipolar, only the variance of the input signal needs to be considered, but the input signal of the visible light communication system is non-negative, and besides the variance, the mean value of the input signal is also an important factor influencing the privacy capacity; low power consumption is generally used as a criterion for selecting an input signal and its distribution in radio frequency communication systems, while visible light communication systems need to meet lighting requirements.
The existing security measures applied to the visible light communication system are as follows: key generation, polarization codes, spread spectrum despreading, beamforming, etc. Goel proposed in 2008 for improving physical layer security of wireless communication by applying an artificial interference technique, which is applied to a visible light communication system by researchers later. The central idea of the artificial interference technology is that an artificial interference signal is generated by using partial power at a transmitting end, the artificial interference signal can be screened and discarded at a legal receiving end, and the eavesdropping end cannot identify the artificial interference signal, so that the error rate of an eavesdropping channel is improved, and effective information received by an eavesdropper is weakened.
Disclosure of Invention
Based on the above-mentioned wiener eavesdropping channel model, the invention constructs a visible light safety communication system based on the artificial interference technology. The system comprises an information sender, a legal receiver and a plurality of illegal eavesdroppers, wherein when the sender and the legal receiver normally communicate, the plurality of eavesdroppers monitor and acquire information in a channel, and the position and the number information of the eavesdroppers are unknown and have no mutual effect. In the system, when the power ratio of the effective signal to the artificial interference signal is 1:1, the secrecy rate of the system reaches the maximum value. The more light sources equipped at the transmitting end of the system, the higher the privacy rate of the system.
Interpretation of terms:
1. VLC, which refers to visible light communications;
2. LED, refers to a light emitting diode;
3. PD, referred to as photodetector;
4. PLS, physical layer secure;
5. TGN, generalized truncated gaussian distribution.
The technical scheme of the invention is as follows:
a visible light safety communication method based on artificial interference technology is operated in a visible light safety communication system, wherein the visible light safety communication system comprises an information sender end, a legal receiver end and a plurality of eavesdropper ends;
the information sender side comprises N LEDs, wherein NtEach LED transmitting a valid signal, NtN/2, addingtThe LEDs are respectively numbered as 1,2, … … and NtThis NtThe signals sent by the LEDs are respectively
Figure BDA0002162137540000021
The effective signal is
Figure BDA0002162137540000022
The rest of N-NtThe LEDs transmit an artificial interference signal, and the N-NtThe LEDs are respectively numbered as 1,2, … … and N-NtThis is N-NtThe signals sent by the LEDs are respectively
Figure BDA0002162137540000031
The artificial interference signal is
Figure BDA0002162137540000032
NtHas a value range of 0 to NtN is less than or equal to N; the legal receiver side comprises a PD; each eavesdropper end comprises a PD, and each PD does not interfere with each other;
the information sender side, the legal receiver side and the eavesdropper side are located in the same space, the position of the legal receiver side is known to the information sender side, the specific position and the number of each eavesdropper side are unknown to the information sender side, a link between the information sender side and the legal receiver side is a legal channel, and a link between the information sender side and the eavesdropper side is an eavesdropper channel; the method comprises the following steps:
(1) according to N of the transmitted effective signaltEstablishing a channel vector h according to the position relationship between the individual LED and the legal receiverB1As shown in formula (I):
Figure BDA0002162137540000033
in the formula (I), the compound is shown in the specification,
Figure BDA0002162137540000034
represents the Nth of the information sender sidetChannel gain between each LED and the PD of the legal receiving terminal;
(2) based on N-N of transmitted artificial interference signalstEstablishing a channel vector h based on the position relationship between the individual LEDs and the legal recipientsB2As shown in formula (II):
Figure BDA0002162137540000035
in the formula (II), the compound is shown in the specification,
Figure BDA0002162137540000036
representing the channel gain between the Nth LED of the information sender end and the PD of the legal receiving end;
(3) establishing N for transmitting valid signalstChannel vector h between individual LED and kth eavesdropper sideE,k,1As shown in formula (III):
Figure BDA0002162137540000037
in the formula (III), the compound represented by the formula (III),
Figure BDA0002162137540000038
represents the Nth of the information sender sidetCommunication between an LED and a PD on the kth eavesdropper sideA track gain;
(4) establishing N-N for transmitting artificial interference signaltChannel vector h between individual LED and kth eavesdropper sideE,k,2As shown in formula (IV):
Figure BDA0002162137540000039
in the formula (IV), the compound is shown in the specification,
Figure BDA00021621375400000310
representing the channel gain between the Nth LED of the information sender side and the PD of the kth eavesdropper;
(5) valid signal
Figure BDA00021621375400000311
After serial-parallel conversion and conversion into bipolar parallel signals, adding direct current bias, raising the signals into non-negative signals, and sequentially loading N effective signal sending signals to the information sender endtA plurality of LEDs;
(6) artificial interference signal
Figure BDA0002162137540000041
After serial-parallel conversion and conversion into bipolar parallel signals, adding direct current bias, raising the signals into nonnegative signals, and sequentially loading the signals to the N-N of the information sender end for sending the artificial interference signalstA plurality of LEDs; according to the artificial interference technique, the signal w is taken from hB2A null space of (a);
(7) the non-negative signal formed in the step (5) and the non-negative signal formed in the step (6) are respectively received and sensed at a legal receiver end and an eavesdropper end after being transmitted in free space;
the legal receiver side receives the non-negative signal formed in the step (5) and the non-negative signal formed in the step (6) at the same time, and the received signal yBAs shown in formula (V):
Figure BDA0002162137540000042
in the formula (V), the compound is shown in the specification,
Figure BDA0002162137540000043
representing white gaussian noise independent of the input signal in a legitimate channel,
Figure BDA0002162137540000044
is the variance of Gaussian white noise; the signal w being taken from hB2Of zero space, i.e.
Figure BDA0002162137540000045
The signal received by the legal receiver is
Figure BDA0002162137540000046
The signal formed in the step (6) is automatically filtered by a legal receiving end, and only the signal formed in the step (5) is processed in the subsequent signal processing;
the eavesdropper receives the non-negative signal formed in the step (5) and the non-negative signal formed in the step (6) at the same time, and the signal received by the kth eavesdropper is as shown in the formula (VI):
Figure BDA0002162137540000047
in the formula (VI), the compound represented by the formula (VI),
Figure BDA0002162137540000048
representing white gaussian noise independent of the input signal in the eavesdropping channel,
Figure BDA0002162137540000049
is the variance of gaussian white noise. Processing the signals formed in steps (5) and (6) simultaneously in a subsequent signal processing;
according to the invention, preferably, the artificial interference technology is used, the secret capacity is calculated, the closer the power ratio of the effective information of the sending end to the artificial interference information is to 1:1, the larger the secret capacity of the system is, and accordingly, the larger security can be obtained by adjusting the power ratioAnd (4) the density is high. Calculating the secret capacity C of a visible light secure communication systemSThe calculation formula is shown as formula (VII):
Figure BDA00021621375400000410
in the formula (VII), H (-) represents the entropy of the information, var (-) represents the variance of the random variable, and the value range of i is more than or equal to 0 and less than or equal to NtJ has a value range of 0 to N-NtThe security capacity represents the maximum security rate. The privacy rate of the visible light secure communication system can be expressed by the lower limit of the privacy capacity.
Preferably, according to the present invention, in step (i), the channel gain is calculated according to the following formula (viii):
Figure BDA0002162137540000051
in the formula (VIII), n is the Lambert coefficient of the LED, and the calculation formula is
Figure BDA0002162137540000052
θ0.5Is an angle corresponding to half of the received total transmission power, namely a half-power angle; FoV is the field angle of the PD; psiFoVRepresents the angle range of the optical signal detected by the corresponding PD; d represents the distance between the corresponding LED and the PD;
Figure BDA0002162137540000053
is the emission angle;
Figure BDA0002162137540000054
is the angle of incidence; a is the effective receiving area of the corresponding PD;
Figure BDA0002162137540000055
filter gain for the legitimate receiver side;
Figure BDA0002162137540000056
for condenser gainAnd (4) the coefficient.
Preferably, according to the present invention, the effective signal and the artificial interference signal formed in steps (3) and (4) have the same mean and variance.
According to the present invention, preferably, the secret capacity of the system is a difference between a channel capacity of a legal channel and a channel capacity of an eavesdropping channel, but the channel capacity of the visible light communication cannot be directly calculated by using shannon's formula, and a calculation process of a lower limit expression of the secret capacity of the visible light secure communication system is shown in formula (ix):
Figure BDA0002162137540000057
in formula (IX), I [ ·; a]Representing the amount of mutual information between the two signals, H (-) representing the entropy of the information,
Figure BDA0002162137540000058
the minimum value that the target function can take is represented, and the minimum value corresponds to the k-th eavesdropper side, namely the k-th eavesdropping channel.
Preferred according to the invention are those of the formula (IX) in which H (y)B| s) is calculated as shown in formula (X):
Figure BDA0002162137540000059
preferred according to the invention are those of the formula (IX) in which H (y)B) Is calculated as shown in formula (XI):
Figure BDA0002162137540000061
preferred according to the invention are those of the formula (IX) in which H (y)E,k| s) is calculated as shown in formula (XII):
Figure BDA0002162137540000062
preferred according to the invention are those of the formula (IX) in which H (y)E,k) The calculation process of (A) is shown in formula (XIII):
Figure BDA0002162137540000063
preferred according to the invention are those of the formula (XIII) in which var (y)E,k) Is calculated as shown in formula (XI V):
Figure BDA0002162137540000064
in the formula (XI V), var(s)i)＝var(wi)。
According to the invention, the useful signal s and the artificial interference signal w are preferably set to mean 0 and variance σ over a range (a, b)2Assuming that the mean of the random variable x is 0 and the variance is σ2In the interval (a, b) according to a Truncated generalized Gaussian (TGN) distribution, the probability distribution function f of the random variable xX(x) As shown in formula (XV):
Figure BDA0002162137540000071
in the formula (XV), phi (-) and phi (-) respectively represent a probability distribution function and a cumulative distribution function of a standard Gaussian distribution,
the entropy H (x) of the random variable x is represented by formula (XVI):
Figure BDA0002162137540000072
in formula (XVI), α ═ a/σ, β ═ b/σ, Z ═ Φ (β) - Φ (α),
Figure BDA0002162137540000073
at this time, the secret rate R of the visible light secure communication systemSRepresented by formula (XVII):
Figure BDA0002162137540000074
according to the invention, the effective signal s and the artificial interference signal w are preferably arranged to be distributed uniformly in the interval (-a, a), and the secret rate R of the visible light safety communication system is setSRepresented by formula (XVIII):
Figure BDA0002162137540000075
according to the invention, the desired signal s and the interference signal w are preferably set to comply with a uniform distribution of the parameter λ, in which case the secret rate R of the visible-light-secure communication systemSRepresented by formula (XIX):
Figure BDA0002162137540000076
in a visible-light secure communication system, the optical power reflected via the ceiling, walls, and other objects in a room has a negligible effect on the legitimate receiver side and the eavesdropper side compared to the optical power of a Line-of-sight (LOS) link, and therefore only the optical power of the LOS link is considered in the channel gain calculation.
The invention has the advantages that
1. The invention constructs a visible light safety communication system model based on the artificial interference technology, and the system can still realize safety communication under the condition of unknown position information and quantity information of the eavesdropper by using the artificial interference technology.
2. The invention calculates the secrecy rate based on the system model, and is beneficial to a user to flexibly select the power ratio of effective information and interference information in the input signal and the quantity of light sources according to the required security level.
Drawings
FIG. 1 is a model diagram of a visible light communication system based on an artificial interference technology;
FIG. 2 is a schematic diagram of a positional relationship between an LED and a PD;
FIG. 3 is a graph illustrating the privacy rates of the input signals with different distributions for a visible light security communication system with a number of LEDs of 20;
FIG. 4 is a graph of security rates for a visible light secure communication system using different numbers of LEDs with TGN profiles as input signals;
fig. 5 is a diagram illustrating an average privacy rate of a visible light secure communication system.
Detailed Description
The invention is further defined in the following, but not limited to, the figures and examples in the description.
Example 1
A visible light safety communication method based on artificial interference technology is operated in a visible light safety communication system, as shown in figure 1, the visible light safety communication system comprises an information sender end, a legal receiver end and a plurality of eavesdropper ends;
the information sender side comprises N LEDs, wherein NtEach LED transmitting a valid signal, NtN/2, addingtThe LEDs are respectively numbered as 1,2, … … and NtThis NtThe signals sent by the LEDs are respectively
Figure BDA0002162137540000081
The effective signal is
Figure BDA0002162137540000082
The rest of N-NtThe LEDs transmit an artificial interference signal, and the N-NtThe LEDs are respectively numbered as 1,2, … … and N-NtThis is N-NtThe signals sent by the LEDs are respectively
Figure BDA0002162137540000083
The artificial interference signal is
Figure BDA0002162137540000084
NtHas a value range of 0 to NtN is less than or equal to N; legal receiverThe terminal comprises a PD; each eavesdropper end comprises a PD, and each PD does not interfere with each other; the positional relationship between the LED and the PD is shown in fig. 2.
The information sender end, the legal receiver end and the eavesdropper end are located in the same space, the position of the legal receiver end is known to the information sender end, the specific position and the number of each eavesdropper end are unknown to the information sender end, a link between the information sender end and the legal receiver end is a legal channel, and a link between the information sender end and the eavesdropper end is an eavesdropper channel; the method comprises the following steps:
(1) according to N of the transmitted effective signaltEstablishing a channel vector h according to the position relationship between the individual LED and the legal receiverB1As shown in formula (I):
Figure BDA0002162137540000085
in the formula (I), the compound is shown in the specification,
Figure BDA0002162137540000086
represents the Nth of the information sender sidetChannel gain between each LED and the PD of the legal receiving terminal;
(2) based on N-N of transmitted artificial interference signalstEstablishing a channel vector h based on the position relationship between the individual LEDs and the legal recipientsB2As shown in formula (II):
Figure BDA0002162137540000091
in the formula (II), the compound is shown in the specification,
Figure BDA0002162137540000092
representing the channel gain between the Nth LED of the information sender end and the PD of the legal receiving end;
(3) establishing N for transmitting valid signalstChannel vector h between individual LED and kth eavesdropper sideE,k,1As shown in formula (III):
Figure BDA0002162137540000093
in the formula (III), the compound represented by the formula (III),
Figure BDA0002162137540000094
represents the Nth of the information sender sidetChannel gain between the individual LEDs and the kth eavesdropper-side PD;
(4) establishing N-N for transmitting artificial interference signaltChannel vector h between individual LED and kth eavesdropper sideE,k,2As shown in formula (IV):
Figure BDA0002162137540000095
in the formula (IV), the compound is shown in the specification,
Figure BDA0002162137540000096
representing the channel gain between the Nth LED of the information sender side and the PD of the kth eavesdropper;
(5) valid signal
Figure BDA0002162137540000097
After serial-parallel conversion and conversion into bipolar parallel signals, adding direct current bias, raising the signals into non-negative signals, and sequentially loading N effective signal sending signals to the information sender endtA plurality of LEDs;
(6) artificial interference signal
Figure BDA0002162137540000098
After serial-parallel conversion and conversion into bipolar parallel signals, adding direct current bias, raising the signals into nonnegative signals, and sequentially loading the signals to the N-N of the information sender end for sending the artificial interference signalstA plurality of LEDs; according to the artificial interference technique, the signal w is taken from hB2A null space of (a);
(7) the non-negative signal formed in the step (5) and the non-negative signal formed in the step (6) are respectively received and sensed at a legal receiver end and an eavesdropper end after being transmitted in free space;
the legal receiver side receives the non-negative signal formed in the step (5) and the non-negative signal formed in the step (6) at the same time, and the received signal yBAs shown in formula (V):
Figure BDA0002162137540000099
in the formula (V), the compound is shown in the specification,
Figure BDA00021621375400000910
representing white gaussian noise independent of the input signal in a legitimate channel,
Figure BDA00021621375400000911
is the variance of Gaussian white noise; the signal w being taken from hB2Of zero space, i.e.
Figure BDA00021621375400000912
The signal received by the legal receiver is
Figure BDA00021621375400000913
The signal formed in the step (6) is automatically filtered by a legal receiving end, and only the signal formed in the step (5) is processed in the subsequent signal processing;
the eavesdropper receives the non-negative signal formed in the step (5) and the non-negative signal formed in the step (6) at the same time, and the signal received by the kth eavesdropper is as shown in the formula (VI):
Figure BDA0002162137540000101
in the formula (VI), the compound represented by the formula (VI),
Figure BDA0002162137540000102
representing white gaussian noise independent of the input signal in the eavesdropping channel,
Figure BDA0002162137540000103
is the variance of gaussian white noise. The signals formed in steps (5) and (6) are processed simultaneously in subsequent signal processing.
Example 2
The visible light safety communication method based on the artificial interference technology in the embodiment 1 is characterized in that:
the artificial interference technology is used, the secrecy capacity can be obtained after the secrecy capacity is calculated, the closer the power ratio of the effective information of the sending end to the artificial interference information is to 1:1, the larger the secrecy capacity of the system is, and accordingly, the larger secrecy capacity can be obtained by adjusting the power ratio. Calculating the secret capacity C of a visible light secure communication systemSThe calculation formula is shown as formula (VII):
Figure BDA0002162137540000104
in the formula (VII), H (-) represents the entropy of the information, var (-) represents the variance of the random variable, and the value range of i is more than or equal to 0 and less than or equal to NtJ has a value range of 0 to N-NtThe security capacity represents the maximum security rate. The privacy rate of the visible light secure communication system can be expressed by the lower limit of the privacy capacity.
Example 3
The visible light safety communication method based on the artificial interference technology in the embodiment 1 is characterized in that:
in the step (I), the channel gain is calculated according to the formula (VIII):
Figure BDA0002162137540000105
in the formula (VIII), n is the Lambert coefficient of the LED, and the calculation formula is
Figure BDA0002162137540000106
θ0.5Is an angle corresponding to half of the received total transmission power, namely a half-power angle; FoV isThe field angle of the PD; psiFoVRepresents the angle range of the optical signal detected by the corresponding PD; d represents the distance between the corresponding LED and the PD;
Figure BDA0002162137540000107
is the emission angle;
Figure BDA0002162137540000108
is the angle of incidence; a is the effective receiving area of the corresponding PD;
Figure BDA0002162137540000111
filter gain for the legitimate receiver side;
Figure BDA0002162137540000112
is the condenser gain factor.
Example 4
The visible light safety communication method based on the artificial interference technology in the embodiment 1 is characterized in that:
the effective signals and the artificial interference signals formed in the steps (3) and (4) have the same mean value and variance.
Example 5
The visible light safety communication method based on the artificial interference technology in the embodiment 1 is characterized in that:
the secret capacity of the system is the difference value between the channel capacity of a legal channel and the channel capacity of an eavesdropping channel, but the channel capacity of the visible light communication cannot be directly calculated by using a shannon formula, and the calculation process of the lower limit expression of the secret capacity of the visible light safety communication system is shown as a formula (IX):
Figure BDA0002162137540000113
in formula (IX), I [ ·; a]Representing the amount of mutual information between the two signals, H (-) representing the entropy of the information,
Figure BDA0002162137540000114
the minimum value that the target function can take is represented, and the minimum value corresponds to the k-th eavesdropper side, namely the k-th eavesdropping channel.
In the formula (IX), H (y)B| s) is calculated as shown in formula (X):
Figure BDA0002162137540000115
in the formula (IX), H (y)B) Is calculated as shown in formula (XI):
Figure BDA0002162137540000116
in the formula (IX), H (y)E,k| s) is calculated as shown in formula (XII):
Figure BDA0002162137540000121
in the formula (IX), H (y)E,k) The calculation process of (A) is shown in formula (XIII):
Figure BDA0002162137540000122
in the formula (XIII), var (y)E,k) Is calculated as shown in formula (XI V):
Figure BDA0002162137540000123
in the formula (XI V), var(s)i)＝var(wi)。
In a visible-light secure communication system, the optical power reflected via the ceiling, walls, and other objects in a room has a negligible effect on the legitimate receiver side and the eavesdropper side compared to the optical power of a Line-of-sight (LOS) link, and therefore only the optical power of the LOS link is considered in the channel gain calculation.
Example 6
The visible light safety communication method based on the artificial interference technology in the embodiment 1 is characterized in that:
setting the mean value of the effective signal s and the artificial interference signal w to be 0 and the variance to be sigma over the interval (a, b)2Assuming that the mean of the random variable x is 0 and the variance is σ2In the interval (a, b) according to a Truncated generalized Gaussian (TGN) distribution, the probability distribution function f of the random variable xX(x) As shown in formula (XV):
Figure BDA0002162137540000124
in the formula (XV), phi (-) and phi (-) respectively represent a probability distribution function and a cumulative distribution function of a standard Gaussian distribution,
the entropy H (x) of the random variable x is represented by formula (XVI):
Figure BDA0002162137540000125
in formula (XVI), α ═ a/σ, β ═ b/σ, Z ═ Φ (β) - Φ (α),
Figure BDA0002162137540000131
at this time, the secret rate R of the visible light secure communication systemSRepresented by formula (XVII):
Figure BDA0002162137540000132
example 7
The visible light safety communication method based on the artificial interference technology in the embodiment 1 is characterized in that:
setting effective signal s and artificial interference signal w to obey uniform distribution in interval (-a, a), at this time, secret rate R of visible light safety communication systemSRepresented by formula (XVII)I) Shown in the figure:
Figure BDA0002162137540000133
example 8
The visible light safety communication method based on the artificial interference technology in the embodiment 1 is characterized in that:
setting the effective signal s and the artificial interference signal w to obey the uniform distribution with the parameter lambda, wherein the secret rate R of the visible light safety communication systemSRepresented by formula (XIX):
Figure BDA0002162137540000134
with the number of LEDs being 20, the privacy rates of the visible light secure communication system using the input signals of different distributions are shown in fig. 3.
Example 9
The visible light safety communication method based on the artificial interference technology in the embodiment 1 is characterized in that:
setting effective information and artificial interference information in interval [ -1,1]The mean value of the TGN distribution is 0, the variance is 0.1225, and the variance of Gaussian noise of a legal receiving end and an eavesdropper end is 10-13The relationship between the secret rate and the effective information ratio is shown in fig. 4. The relation between the average security rate and the ratio of the effective information is shown in fig. 5, and the result shows that when the ratio of the effective signal and the artificial interference signal of the system is determined, the average security rate of the system can be improved by increasing the number of light sources of the system. When the number of light sources of the system is determined, the average privacy rate of the system can reach the maximum value when the power ratio of the effective signal to the artificial interference signal is controlled to be 1: 1.

Claims (10)

1. A visible light safety communication method based on artificial interference technology is characterized by operating in a visible light safety communication system, wherein the visible light safety communication system comprises an information sender end, a legal receiver end and a plurality of eavesdropper ends;
the information sender side comprises N LEDs, wherein NtEach LED transmitting a valid signal, NtN/2, addingtThe LEDs are respectively numbered as 1,2, … … and NtThis NtThe signals sent by the LEDs are respectively
Figure FDA0003117087020000011
The effective signal is
Figure FDA0003117087020000012
The rest of N-NtThe LEDs transmit an artificial interference signal, and the N-NtThe LEDs are respectively numbered as 1,2, … … and N-NtThis is N-NtThe signals sent by the LEDs are respectively
Figure FDA0003117087020000013
The artificial interference signal is
Figure FDA0003117087020000014
NtHas a value range of 0 to NtN is less than or equal to N; the legal receiver side comprises a PD; each eavesdropper end comprises a PD, and each PD does not interfere with each other; LED, refers to a light emitting diode; PD, referred to as photodetector;
the information sender side, the legal receiver side and the eavesdropper side are located in the same space, the position of the legal receiver side is known to the information sender side, the specific position and the number of each eavesdropper side are unknown to the information sender side, a link between the information sender side and the legal receiver side is a legal channel, and a link between the information sender side and the eavesdropper side is an eavesdropper channel; the method comprises the following steps:
(1) according to N of the transmitted effective signaltEstablishing a channel vector h according to the position relationship between the individual LED and the legal receiverB1As shown in formula (I):
Figure FDA0003117087020000015
in the formula (I), the compound is shown in the specification,
Figure FDA0003117087020000016
represents the Nth of the information sender sidetChannel gain between individual LEDs and the PD of the legitimate recipient end;
(2) based on N-N of transmitted artificial interference signalstEstablishing a channel vector h based on the position relationship between the individual LEDs and the legal recipientsB2As shown in formula (II):
Figure FDA0003117087020000017
in the formula (II), the compound is shown in the specification,
Figure FDA0003117087020000018
representing the channel gain between the Nth LED of the information sender end and the PD of the legal receiver end;
(3) establishing N for transmitting valid signalstChannel vector h between individual LED and kth eavesdropper sideE,k,1As shown in formula (III):
Figure FDA0003117087020000019
in the formula (III), the compound represented by the formula (III),
Figure FDA0003117087020000021
represents the Nth of the information sender sidetChannel gain between the individual LEDs and the kth eavesdropper-side PD;
(4) establishing N-N for transmitting artificial interference signaltChannel vector h between individual LED and kth eavesdropper sideE,k,2As shown in formula (IV):
Figure FDA0003117087020000022
in the formula (IV), the compound is shown in the specification,
Figure FDA0003117087020000023
representing the channel gain between the Nth LED of the information sender side and the PD of the kth eavesdropper;
(5) valid signal
Figure FDA0003117087020000024
After serial-parallel conversion and conversion into bipolar parallel signals, adding direct current bias, raising the signals into non-negative signals, and sequentially loading N effective signal sending signals to the information sender endtA plurality of LEDs;
(6) artificial interference signal
Figure FDA0003117087020000025
After serial-parallel conversion and conversion into bipolar parallel signals, adding direct current bias, raising the signals into nonnegative signals, and sequentially loading the signals to the N-N of the information sender end for sending the artificial interference signalstA plurality of LEDs; the signal w being taken from hB2A null space of (a);
(7) the non-negative signal formed in the step (5) and the non-negative signal formed in the step (6) are respectively received and sensed at a legal receiver end and an eavesdropper end after being transmitted in free space;
the legal receiver side receives the non-negative signal formed in the step (5) and the non-negative signal formed in the step (6) at the same time, and the received signal yBAs shown in formula (V):
Figure FDA0003117087020000026
in the formula (V), the compound represented by the formula (V),
Figure FDA0003117087020000027
representing input signal independent white gaussian noise in a legitimate channelThe sound is generated by the sound generator,
Figure FDA0003117087020000028
is the variance of Gaussian white noise; the signal w being taken from hB2Of zero space, i.e.
Figure FDA0003117087020000029
The signal received by the legal receiver is
Figure FDA00031170870200000210
The eavesdropper receives the non-negative signal formed in the step (5) and the non-negative signal formed in the step (6) at the same time, and the signal received by the kth eavesdropper is as shown in the formula (VI):
Figure FDA00031170870200000211
in the formula (VI), the compound represented by the formula (VI),
Figure FDA00031170870200000212
representing white gaussian noise independent of the input signal in the eavesdropping channel,
Figure FDA00031170870200000213
is the variance of gaussian white noise.
2. The visible light secure communication method based on the artificial interference technology as claimed in claim 1, wherein the secret capacity C of the visible light secure communication system is calculatedSThe calculation formula is shown as formula (VII):
Figure FDA0003117087020000031
in the formula (VII), H (-) represents the entropy of the information, var (-) represents the variance of the random variable, and the value range of i is more than or equal to 0 and less than or equal to NtValue range of jJ is more than or equal to 0 and less than or equal to N-NtThe security capacity represents the maximum security rate.
3. The method for visible light secure communication based on artificial interference technology as claimed in claim 1, wherein in step (i), the channel gain is calculated according to formula (viii):
Figure FDA0003117087020000032
in the formula (VIII), n is the Lambert coefficient of the LED, and the calculation formula is
Figure FDA0003117087020000033
θ0.5Is an angle corresponding to half of the received total transmission power, namely a half-power angle; FoV is the field angle of the PD; psiFoVRepresents the angle range of the optical signal detected by the corresponding PD; d represents the distance between the corresponding LED and the PD;
Figure FDA0003117087020000034
is the emission angle;
Figure FDA0003117087020000035
is the angle of incidence; a is the effective receiving area of the corresponding PD;
Figure FDA0003117087020000036
filter gain for the legitimate receiver side;
Figure FDA0003117087020000037
is the condenser gain factor.
4. The visible light secure communication method based on the artificial interference technology as claimed in claim 1, wherein the effective signal and the artificial interference signal formed in steps (3) and (4) have the same mean and variance.
5. The visible light security communication method based on the artificial interference technology as claimed in claim 1, wherein the calculation procedure of the lower limit expression of the privacy capacity of the visible light security communication system is shown in formula (ix):
Figure FDA0003117087020000038
in formula (IX), I [ ·; a]Representing the amount of mutual information between the two signals, H (-) representing the entropy of the information,
Figure FDA0003117087020000039
the minimum value that the target function can take is represented, and the minimum value corresponds to the k-th eavesdropper side, namely the k-th eavesdropping channel.
6. The visible light security communication method based on artificial interference technique according to claim 5, wherein in formula (IX), H (y)B| s) is calculated as shown in formula (X):
Figure FDA00031170870200000310
in the formula (IX), H (y)B) The calculation process of (A) is shown in formula (XI):
Figure FDA0003117087020000041
in the formula (IX), H (y)E,k| s) is calculated as shown in formula (XII):
Figure FDA0003117087020000042
in the formula (IX), H (y)E,k) The calculation process of (A) is shown as formula (XIII):
Figure FDA0003117087020000043
7. the visible light safety communication method based on artificial interference technology as claimed in claim 6, wherein in formula (XIII), var (y)E,k) Is shown in formula (XIV):
Figure FDA0003117087020000044
in formula (XIV), var(s)i)＝var(wi)。
8. The visible light safety communication method based on artificial interference technology as claimed in claim 1, wherein the effective signal s and the artificial interference signal w are set to obey a mean value of 0 and a variance of σ in intervals (a, b)2Assuming that the mean of the random variable x is 0 and the variance is σ2In the interval (a, b) according to truncated generalized Gaussian distribution, the probability distribution function f of the random variable xX(x) As shown in formula (XV):
Figure FDA0003117087020000051
in the formula (XV), phi (-) and phi (-) respectively represent a probability distribution function and a cumulative distribution function of a standard Gaussian distribution,
the entropy H (x) of the random variable x is represented by formula (XVI):
Figure FDA0003117087020000052
in formula (XVI), α ═ a/σ, β ═ b/σ, Z ═ Φ (β) - Φ (α),
Figure FDA0003117087020000053
at this time, the secret rate R of the visible light secure communication systemSRepresented by formula (XVII):
Figure FDA0003117087020000054
9. the method according to claim 1, wherein the valid signal s and the artificial interference signal w are arranged to obey a uniform distribution over the interval (-a, a), and at this time, the secret rate R of the visible light secure communication system is setSRepresented by formula (XVIII):
Figure FDA0003117087020000055
10. the method according to any one of claims 1-9, wherein the valid signal s and the artificial interference signal w are set to obey a uniform distribution with a parameter λ, and at this time, the secret rate R of the visible light secure communication systemSRepresented by formula (XIX):
Figure FDA0003117087020000056
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106788961A (en) * 2016-12-12 2017-05-31 中山大学 A kind of high security Orthogonal Decomposition Chaotic Scrambling method based on positional information

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Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106788961A (en) * 2016-12-12 2017-05-31 中山大学 A kind of high security Orthogonal Decomposition Chaotic Scrambling method based on positional information

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Optical Jamming Enhances the Secrecy Performance of the Generalized Space-Shift-Keying-Aided Visible-Light Downlink;Fasong Wang;《IEEE Transactions on Communications》;20180430;全文 *
Physical-Layer Security for Indoor Visible Light Communications;Ayman Mostafa;《2014 IEEE International Conference on Communications (ICC)》;20140828;全文 *
Securing Visible Light Communications via Friendly Jamming;Ayman Mostafa;《2014 IEEE Globecom Workshops (GC Wkshps)》;20150319;全文 *

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